JP2015049551A - Biometric authentication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems, for example, when a user is placed in a shape that authentication of the living body shape is disadvantageous for authentication, biometric information cannot be acquired correctly, resulting in difficulty of authentication.SOLUTION: The biometric authentication device comprises: a living body installation part for installing a living body of a user; a light source part for radiating light to the living body installed on the living body installation part; two or more imaging parts for imaging transmitted light which transmitted the living body and which is light radiated from the light source part; and a control part controlling them. The imaging parts images a first living body image used for living body authentication and a second living body image for calculating a correction coefficient for correcting the first living body image, and the control part calculates the correction coefficient, and corrects the first living body image using the correction coefficient.

Description

  The present invention relates to a biometric authentication device.

  Biometric authentication devices that authenticate users using biometric information are used in various devices and systems. When the user is authenticated by the biometric authentication device, the user reads the biometric information by performing an operation of holding a predetermined part of the body such as a finger or an eye over the authentication device or a peeping operation (authentication operation), and the biometric information is extracted from the biometric information. The matching amount is calculated by comparing the feature amount with the feature amount of the biometric information registered in advance by the person, and the person is determined based on whether the degree of matching exceeds a predetermined threshold.

  When performing the personal authentication in the biometric authentication device, one of the factors that cause the person to be rejected by mistake even though the person is the registrant is a different way of placing the biometric at the time of registration. There are cases. There exists Unexamined-Japanese-Patent No. 2009-178300 (patent document 1) as background art of this technical field. In this publication, “a finger placed on a placement board is imaged by a finger position detection camera, the position of the finger is detected from the image information, and the quality of the finger is determined. Is determined to be defective, a screen for guiding the user to correctly place the finger on the placing plate 2 is displayed on the display unit.

JP 2009-178300 A

  When the technique described in Patent Document 1 is used, it is possible to acquire biological information at a correct position. However, since it is a device that instructs the user to reposition the living body, if the user places the form of the living body in a disadvantageous form for authentication, the biometric information cannot be obtained correctly and authentication becomes difficult. There is a case. For example, when the living body is deformed, such as a case where the living body is tilted or a case where a living body is bent, authentication becomes difficult because the living body information is also deformed.

  Therefore, the present invention provides a biometric authentication apparatus that performs biometric information acquisition and performs authentication even when a biometric is not correctly installed when a user places the biometric.

  In order to solve the above problems, the present invention provides a living body installation unit in which a user's living body is installed, a light source unit that irradiates light to the living body installed in the living body installation unit, and light emitted from the light source unit. The imaging unit includes two or more imaging units that capture the transmitted light that has passed through the living body and a control unit that controls them. The imaging unit captures the first biological image and the first biological image that are used for biometric authentication. The second biometric image for calculating the correction coefficient to be corrected is captured, the control unit has a biometric authentication device that calculates the correction coefficient and corrects the first biometric image using the correction coefficient.

  According to the present invention, when the shape of the living body is detected by the imaging device mounted in the biometric authentication device, and the state of the living body is in a shape unfavorable for authentication, such as inclination of the living body, bending of a joint, or warping. The biometric information is corrected according to the state of the biometric, and authentication is possible, thereby improving the convenience of the biometric authentication device.

It is an example of the figure which shows the external appearance of a biometrics authentication apparatus. It is an example of the block diagram which shows the apparatus structure of a biometrics authentication apparatus. It is an example of sectional drawing which shows arrangement | positioning of the component of a biometrics apparatus. It is an example of the top view which shows arrangement | positioning of the component of a biometrics apparatus. It is an example of the flowchart of the registration process which registers the biometric information of a biometrics authentication apparatus. It is an example of the flowchart of the authentication process which authenticates the biometric information of a biometrics authentication apparatus. It is an example of the figure explaining the biometric image imaged by each imaging part. It is an example of the figure explaining the outline detection of a biometric image. It is an example of the figure explaining the detection of the inclination of a biological information, and a bending from the image of a biological image. It is an example of a figure explaining image correction of a living body image. It is an example of the flowchart explaining the authentication process of a biometrics authentication apparatus. It is an example of the figure which shows arrangement | positioning of the component of a biometrics authentication apparatus. It is an example of the flowchart of the authentication process which authenticates the biometric information of a biometrics authentication apparatus. It is an example of the figure which shows arrangement | positioning of the component of a biometrics authentication apparatus. It is an example of the figure which shows the external appearance of a biometrics authentication apparatus.

  Hereinafter, examples will be described with reference to the drawings.

A. Apparatus Configuration An embodiment of the present invention will be described with reference to FIGS. First, the configuration of the biometric authentication device 100 in the present embodiment will be described. FIG. 1 is an external view of a biometric authentication device 100 according to the present embodiment. As shown in FIG. 1, the biometric authentication device 100 includes a light source unit 103, a fingertip installation unit 105, a fingertip installation unit 106, and an opening 107.

  The fingertip installation unit 105 supports the fingertip of the user's living body 301, and the fingertip installation unit 105 is a support unit that supports the base of the finger of the living body 301. The light source unit 103 includes an infrared LED that emits near-infrared light, and irradiates infrared rays from the left and right to the user's finger installed (supported) on the fingertip installation unit 105 and the fingertip installation unit 106. The opening 107 guides transmitted light of near-infrared light emitted from the light source unit 103 to a first imaging unit 101 and a second imaging unit 102 described later. The opening may include a filter that cuts out external light, an acrylic panel that prevents dust from entering, and the like.

  That is, the biometric authentication device 100 irradiates infrared rays from the light source unit 103 from both sides of the installed biological body 301 by installing the user's biological body 301 (finger) in the fingertip installation unit 105 and the fingertip installation unit 106. The light transmitted through the living body 301 passes through the opening 107 and is imaged by the first imaging unit 101 and the second imaging unit 102 located below the opening 107, whereby the user's biological information (biological image) is obtained. Shoot (acquire).

  FIG. 2 is a functional block diagram illustrating functional blocks of the biometric authentication device 100 according to the present embodiment. In the biometric authentication device 100, the first imaging unit 101, the second imaging unit 102, the light source unit 103, and the communication unit 104 are controlled by the control unit 110. In addition, the biometric authentication device 100 is connected to the upper terminal 200 via the communication unit 104. For example, if the biometric authentication device 100 of this embodiment is incorporated in an ATM (Automated Teller Machine) installed in a financial institution or a convenience store, the host terminal 200 corresponds to the ATM. Further, for example, if the biometric authentication device 100 is a terminal placed at a financial institution's window, a clerk terminal used by a clerk corresponds to the host terminal 200.

  The first image capturing unit 101 and the second image capturing unit 102 are image capturing units that capture the transmitted light guided from the opening 107. The light source unit 103 is configured by an infrared LED or the like that can irradiate near-infrared light, and the irradiation timing and light amount of the infrared LED are controlled by the control unit 110. Therefore, the living body can be imaged by taking into consideration the influence of external light or the like by the light amount control by the control unit 110.

  The communication unit 104 is biometric data (also referred to as biometric information for registration) in which biometric information captured by the first image capturing unit 101 and the second image capturing unit 102 is in a state suitable for registration by processing of the control unit 110 described later. Is transmitted to the upper terminal 200. Also, biometric data for authentication (also referred to as biometric information for authentication) is received from the upper terminal 200.

  The control unit 110 is a control unit that controls each unit connected to the control unit 110. Also, registration processing and authentication processing of the user's biometric information are performed. For example, the light quantity of the light source unit 103 is adjusted to a state suitable for imaging of a living body, and each unit of the biometric authentication device 100 is controlled, and the first imaging unit 101 and the second imaging unit 102 use the user. The living body is imaged. Thereafter, a blood vessel pattern serving as characteristic information at the time of personal authentication is extracted from the biometric image acquired by the first imaging unit 101, and the extracted blood vessel pattern is output as registration data to the upper terminal 200 via the communication unit 104. . At this time, the shape of the living body is detected from the biological image acquired by the second imaging unit 102, and the output of the biological data is stopped when the state of the biological body is unsuitable for registration. This series of processing is also called registration processing. Further, a blood vessel pattern may be acquired from a biological image acquired by the second imaging unit 102.

  In addition, the degree of coincidence is calculated by comparing the extracted blood vessel pattern with registered data registered in advance, identity authentication is performed based on whether the calculated degree of coincidence exceeds a predetermined threshold, and the authentication result is transmitted to the communication unit 104. To the upper terminal 200. This series of processing is also called authentication processing. The control unit 110 includes a storage medium such as a CPU and a memory (not shown), and develops a program in the memory and performs image processing of a biological image captured by the processing of the CPU.

  Note that details of the correction of the biological image captured by the first imaging unit 101 will be described later. In addition, a sensor for detecting pressure may be provided in the fingertip installation unit 105 or the fingertip installation unit 106, and the control unit 110 may detect the output signal of the sensor to control the infrared irradiation timing of the light source unit 104. .

  Next, arrangement of components of the biometric authentication device 100 in the present embodiment will be described. FIG. 3A is a cross-sectional view showing the arrangement of each component of the biometric authentication device 100 in the present embodiment. FIG. 3B is a top view showing the arrangement of each component of the biometric authentication device 100. The light source unit 103 irradiates near infrared light from both side surfaces of the living body 301 indicating a user's finger. As shown in FIG. 3, the first imaging unit 101 is disposed at a position where the center front of the biological part 301 can be imaged, and the second imaging unit 102 is disposed at a position where the side surface of the biological part 301 can be imaged. . In FIG. 3B, a plurality of light source units 103 are provided on one side, but one or a single plate-like light source may be used.

  In other words, the first imaging unit 101 is located below the opening 107 at the center where the light source unit 103 and the axis passing through the center of the biometric authentication device 100 (or the opening 107) intersect, and the second imaging unit 102 is , Located in the vicinity of the first imaging unit 101 (desirably, an axis parallel to the short side of the biometric authentication device 100 and coaxial with the first imaging unit 101).

In addition, the image which image | photographed the center front of the biological body part 301 is called 1st biological image, and the image which image | photographed the side surface of the biological body part 301 is called 2nd biological image. The first biometric image is also called a biometric authentication image, and the second biometric image is also called a correction image. In FIG. 3A, the first imaging unit 101 captures the first biological image. However, as shown in FIG. 11, the second imaging unit 102 captures the first biological image. In some cases.
B. Biometric Information Registration Process The biometric information registration process of the biometric authentication apparatus 100 in this embodiment will be described. FIG. 4 is a flowchart of a registration process using the biometric authentication device 100 according to this embodiment.

  In step 101, it is detected that the user's biometric 301 is placed on the biometric authentication device 100. While it is determined that the living body 301 is not placed, step 101 is repeated (step 102: no living body), and when the living body 301 is placed, the process proceeds to the next step (step 102: living body is present). In step 102, the light amount of the light source unit 103 mounted on the biometric authentication device 100 is adjusted to a state suitable for imaging the living body 301, and then the biometric image is obtained using the first imaging unit 101 and the second imaging unit 102. Get each.

In step 103, the second imaging unit 102 detects the inclination of the living body using the second living body image obtained by imaging the side surface of the living body 301. Details of the tilt detection of the living body 301 will be described later. When it is detected that the living body 301 is tilted beyond a specified angle, it is determined that the living body 301 is not suitable for registration, and therefore the registration process is stopped (step 103: with tilt). If the living body 301 is not inclined at the specified angle, the process proceeds to the next step (step 103: no inclination).
Next, in step 104, the second imaging unit 102 detects bending of the living body 301 using the second living body image obtained by imaging the side surface of the living body 301. Details of the bending detection of the living body 301 will be described later. When it is detected that the joint of the living body 301 is bent beyond a predetermined angle, it is determined that the joint is not suitable for registration, and therefore the registration process is stopped (step 104: bent). If the joint of the living body is not bent beyond the specified angle, the process proceeds to the next step (step 104: no bend).

In step 105, the first imaging unit 101 uses the first biological image obtained by imaging the front surface of the living body 301, and extracts a blood vessel pattern serving as feature information at the time of personal authentication. In step 106, the blood vessel pattern extracted in step 105 is converted into a data form suitable for collation for personal authentication, and this is output to the host terminal 200 as biometric registration data. With the above steps, the registration process is completed.
C. Biometric Information Authentication Process The biometric authentication process of the biometric authentication apparatus 100 in this embodiment will be described. FIG. 5 is an authentication processing flowchart of biometric authentication using the biometric authentication device 100 according to the present embodiment.

  In step 201, biometric registration data passed from the upper terminal 200 via the communication unit 104 is received. At this time, the biometric registration data delivered from the host terminal 200 is biometric registration data registered in advance in the above registration process. In step 202, it is detected that the biometric 301 is placed on the biometric authentication device 100. While it is determined that the living body 301 is not placed, step 202 is repeated (step 202: no living body), and when the living body 301 is placed, the process proceeds to the next step (step 202: living body is present).

  In step 203, the light quantity of the light source unit 103 mounted on the biometric authentication device 100 is adjusted to a state suitable for imaging of the living body 301, and then the biometric image is obtained using the first imaging unit 101 and the second imaging unit 102. Get each. In step 204, the second imaging unit 102 detects the inclination of the living body 301 using the second living body image obtained by imaging the side surface of the living body 301. When it is detected that the living body 301 is tilted beyond a specified angle, the process proceeds to step 205 (step 204: with tilt), and when it is not tilted, the process proceeds to step 206 (step 204: no tilt).

  In step 206, biological inclination correction processing is performed. When the living body 301 is tilted and placed on the biometric authentication device 100, the first living body image obtained by imaging the central front surface of the living body 301 becomes an image distorted into a trapezoid according to the tilt of the living body 301. By correcting the first biological image by image processing so as to be equal to the state in which the living body 301 is placed straight without being inclined, a biological image having no inclination can be obtained. After the inclination correction is performed, the determination process of step 204 is performed again, and the process proceeds to the next step 206.

  In step 206, the second imaging unit 102 detects the bending of the joint of the living body 301 using the second living body image obtained by imaging the side surface of the living body 301. When it is detected that the joint of the living body 301 is bent beyond a predetermined angle, the process proceeds to step 207 (step 206: with a bend), and when not bent, the process proceeds to step 208 (step 206: no bend).

  In step 207, the bending correction process of the living body 301 is performed. When the joint of the living body 301 is bent and placed on the biometric authentication device 100, the first living body image obtained by imaging the center front of the living body 301 becomes an image distorted in a trapezoidal shape in two directions with the joint position of the living body 301 as a boundary. . By correcting the first biological image by image processing so as to be equal to the state where the joint of the living body 301 is placed straight without bending, a biological image without bending can be obtained.

  In step 208, a blood vessel pattern for verification is extracted using a biological image having no inclination or bending. In step 209, blood vessel pattern matching processing is performed. Using biometric registration data registered in advance and the matching blood vessel pattern obtained in step 208, matching is performed by pattern matching to calculate the degree of coincidence. In step 210, authentication is determined from the degree of coincidence obtained in step 209, and the determination result is output to the upper terminal. The authentication process is completed by the above steps.

In the flow chart of FIG. 5, after detecting the tilt of the finger (step 204), the flow of detecting the bending of the finger (step 206) is shown, but the bending of the finger is first detected to correct the bending. The tilt of the finger may be detected. In the flowchart of FIG. 5, the finger inclination is detected again after correcting the finger inclination. However, the process may proceed to a step of detecting the bending of the finger without detecting the inclination. If the tilt does not occur simultaneously, the blood vessel pattern may be extracted without proceeding to the step of detecting the bending of the finger. The same applies to the flowchart of another embodiment described later.
D. Imaging of Biological Image FIG. 6 is a diagram for describing imaging of a biological image in step 102 or step 203. After the light amount of the light source unit 103 mounted on the biometric authentication device 100 is adjusted to a state suitable for imaging the living body 301, a biometric image is captured using the first imaging unit 101 and the second imaging unit 102. At this time, the first imaging unit 101 obtains a first living body image 501 obtained by imaging the center front of the living body. Further, a second living body image 502 obtained by capturing the side surface of the living body is obtained from the second imaging unit.
E. Inclination and bending detection of living body Step 103 Inclination detection of living body 301, Step 104 Inclination detection of living body 301, Step 204 Inclination detection of living body 301 or Step 205 Inclination detection of living body 301 and joint of living body 301 The bending detection method will be described with reference to FIGS.

  FIG. 7 is a diagram for describing processing for detecting the contour position of the living body 301 captured from the second living body image 502. In the contour detection processing of the living body 301, a second living body image 502 obtained by imaging the side surface of the living body 301 is used. The second living body image 502 has high brightness (white) inside the living body and low brightness (black) in the background portion. Therefore, in the contour line extraction process, the second image 502 is scanned from the lower end (601), and the point where the luminance value changes is extracted, thereby detecting the contour position coordinate 602. In addition, although the place where the brightness changed first by operating from the lower end is extracted as the contour line, the point where the brightness changed the second time (the contour line on the upper side of the finger) may be used as the contour position coordinates.

  FIG. 8 is a diagram for explaining the detection of the tilt of the living body 301 or the bending of the living body 301 from the second living body image 502. As shown in FIG. 8A, when the approximate straight line 701 is obtained by using the contour position coordinates 602 of the living body, the control unit 110, when the inclination angle of the recent straight line 701 does not exceed the prescribed angle. It is determined that the living body 301 is placed straight. If the inclination angle of the recent straight line 701 exceeds a specified angle, it is determined that the living body 301 is placed at an inclination. FIG. 8B shows that the living body 301 on the fingertip installation unit 106 side is floated more than the fingertip installation unit 105 side. The tilt angle is an angle formed between the approximate straight line 701 and the lower end of the second biological image 502.

When the two approximate lines 702 and 703 are obtained using the contour position coordinates 602 of the living body 301 as shown in FIG. 8C, the control unit 110 calculates the angle formed by the approximate lines 702 and 703. When the angle exceeds the prescribed angle, it is determined that the joint of the living body 301 is placed with bending. At this time, the position where the approximate lines 702 and 703 intersect is detected as the joint position 704 of the living body 301.
F. Correction of Biological Image The correction process of the first biological image 501 in the inclination correction of the living body 301 in step 206 and the bending correction of the living body in step 207 will be described with reference to FIGS. When the living body 301 is placed straight as shown in FIG. 8A, it is determined that the living body 301 is placed in an appropriate state, and there is no inclination or bending as it is from the first living body image 501. A biological image 801 is obtained.

  When the living body 301 is placed at an angle, the first living body image 501 has a trapezoidal shape because the fingertip installation unit 106 side of the living body 301 is lifted as shown in FIG. 9B. Therefore, the first living body image 501 is corrected according to the tilt angle by image processing so that the living body 301 is equal to a state where the living body 301 is placed straight without tilting. By performing the correction, it is possible to obtain a biological image having no inclination. The correction method will be described in more detail. As a method for correcting the first biological image 501, an inclination angle calculated when obtaining the approximate straight line in FIG. 8B is used. Since the tilt angle corresponds to the trapezoidal distortion of the first biological image 501, a correction coefficient corresponding to the tilt angle is calculated to correct the trapezoidal distortion.

  When the joint of the living body 301 is bent and placed, as shown in FIG. 9C, the first living body image 501 has a shape in which two trapezoids are combined with the joint position 704 of the living body 301 as a boundary. Therefore, in order to correct the image of the first living body image 501, the image processing is performed so that each of the images is equal to a state in which the living body is placed straight, with the joint position 704 of the living body 301 being divided into left and right. By performing correction according to the bending angle, a living body image without bending of the living body can be obtained. It should be noted that the joint position 704 of the living body 301 is obtained from a point where two approximate lines calculated at the time of detecting the bending of the living body 301 intersect. That is, a point corresponding to a point where two approximate straight lines intersect exists on the first biological image 501, and a straight line passing through the point is the joint position 704. As the inclination angle corresponding to the correction coefficient for correcting the left and right trapezoidal shapes, the inclination calculated when the approximate straight line 703 and the approximate straight line 704 are obtained is used.

  As described above, the installation state of the living body 301 is detected by using the first imaging unit 101 and the second imaging unit 102, and the state of the living body 301 (the inclination of the living body 301, the bending of the joint, etc.) is used for authentication. When the shape is unfavorable, it is possible to obtain biometric information suitable for authentication by correcting the biometric information according to the state of the biometric 301, and the convenience of the biometric authentication device can be improved.

  Further, by using the second biological image 502 captured by the second imaging unit 102, it is possible to specify the inclination of the living body and the indirect position 704, so that the biological image can be corrected more accurately. This makes it possible to perform keystone correction with a reduced acceptance rate, unlike the keystone correction conventionally performed with a predetermined value. The other person acceptance rate means that the other person's living body is mistakenly accepted as the person himself at the time of 1: N authentication or the like.

  Hereinafter, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment, the blood vessel pattern is extracted after the first biological image 501 is corrected in the authentication process to obtain a biological image 801 having no inclination or bending. In the second embodiment, the blood vessel pattern that is the opposite is extracted, and then the blood vessel pattern image is corrected and collation processing is performed. In addition, since the structure of Example 1 and the biometrics authentication apparatus 100 is the same, description is abbreviate | omitted.

  In step 301, biometric registration data passed from the upper terminal 200 via the communication unit 104 is received. At this time, the biometric registration data delivered from the host terminal 200 is biometric registration data registered in advance in the registration process. In step 302, it is detected that the living body 301 is placed on the biometric authentication device 100. While it is determined that the living body 301 is not placed, step 302 is repeated (step 302: no living body), and when the living body 301 is placed, the process proceeds to the next step (step 302: living body is present).

  In step 303, the light amount of the light source unit 103 mounted on the biometric authentication device 100 is adjusted to a state suitable for imaging of the living body 301, and then the biometric image is obtained using the first imaging unit 101 and the second imaging unit 102. Get each. In step 304, a blood vessel pattern is extracted from the first biological image 501 to obtain a blood vessel pattern image. In step 305, the inclination of the living body 301 is detected using the second living body image 502 obtained by imaging the side surface of the living body 301. When it is detected that the living body 301 is tilted beyond a specified angle, the process proceeds to step 306 (step 305: with tilt), and when it is not tilted, the process proceeds to step 307 (step 305: without tilt).

  In step 306, the blood vessel pattern image is corrected according to the inclination of the living body 301. When the living body 301 is tilted and placed on the biometric authentication device 100, the blood vessel pattern image obtained in step 304 becomes a trapezoidally distorted image according to the tilt of the living body 301. Therefore, the inclination is obtained by performing correction by image processing. It is possible to obtain a blood vessel pattern image having no image. After the inclination correction is performed, the determination process in step 305 is performed again, and the process proceeds to the next step 307.

  In step 307, the bending of the joint of the living body 301 is detected using the second living body image 502 obtained by imaging the side surface of the living body 301. When it is detected that the joint of the living body 301 is bent beyond the specified angle, the process proceeds to Step 308 (Step 307: There is a bend), and when it is not bent, the process proceeds to Step 309 (Step 307: No bend).

  In step 308, the blood vessel pattern image is corrected according to the bending of the living body 301. When the biometric authentication apparatus 100 is placed with a living body bent, the blood vessel pattern image obtained in step 305 is an image distorted in a trapezoidal shape in two directions with the joint position of the living body 301 as a boundary according to the bending of the living body 301. Therefore, a blood vessel pattern image without bending can be obtained by performing correction by image processing.

  In step 309, blood vessel pattern matching processing is performed. Using bioregistration data registered in advance and a blood vessel pattern image without inclination and bending obtained up to step 308, matching by pattern matching is performed to calculate the degree of coincidence.

  In step 310, authentication is determined from the degree of coincidence obtained in step 309, and the determination result is output to the upper terminal 200. With the above steps, the authentication process in the second embodiment is completed.

  As described above, the state of the living body 301 is detected by the first imaging unit 101 and the second imaging unit 102, and the state of the living body 301 (the inclination of the living body 301, the bending of the joint, etc.) is in a disadvantageous form for authentication. If it is, the blood vessel pattern image is corrected in accordance with the state of the living body 301 to obtain a blood vessel pattern suitable for authentication, thereby enabling authentication processing with a reduced processing amount compared to the case of correcting the biological image. It becomes. That is, since the blood vessel pattern image is smaller in size than the first biological image 501 captured by the first imaging unit 101, the performance (for example, CPU speed) of the control unit 110 is compared with the case where the first biological image 501 is handled. Can be suppressed. Further, since the processing amount is reduced, the time required for the authentication process can be shortened.

  Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. In the first embodiment, as illustrated in FIG. 6, the first imaging unit 101 acquires a first biological image 501 that is a front image of the living body 301, and the second imaging unit 102 is a side image of the living body 301. The example which acquires a certain 2nd biological image 502 was demonstrated. In the third embodiment, as shown in FIG. 11, when the living body 301 rotates about the axis in the fingertip direction from the base of the finger (an axis parallel to the long side of the biometric authentication device 100) (also referred to as rolled). An authentication process of the biometric authentication device 100 will be described. In addition, since the structure of Example 1 and the biometrics authentication apparatus 100 is the same, description is abbreviate | omitted.

  FIG. 11 is a diagram illustrating a state in which the living body 301 is rotated clockwise by a predetermined angle about an axis in the fingertip direction from the fingertip. In this case, unlike the first embodiment, the first imaging unit 101 can image the side surface of the living body 301, and the second imaging unit 102 can image the front surface of the living body 301. As described above, when the living body 301 rolls, one of the images captured by the first imaging unit 101 and the second imaging unit 102 is a front image of the living body 301 (first biological image or biometric authentication image). Or one of them is a side image (second biological image or correction image) of the living body 301.

FIG. 12 is a diagram illustrating an authentication processing flow of the biometric authentication device 100 according to the third embodiment. Steps 401 to 403 in FIG. 12 are the same as in the description of the first embodiment, and are therefore omitted.
After the biometric image is captured, the biometric authentication device 100 performs imaging site determination in order to identify which part of the living body 301 is captured by the first imaging unit 101 and the second imaging unit 102 (step 404). .

  A specific method for determining the imaging region will be described. The control unit 110 calculates an approximate straight line of the outline of the living body for each of the image 101 captured by the first imaging unit and the image captured by the second imaging unit 102, and calculates an inclination angle or a bending angle. Next, the inclination angle or the bending angle calculated from the approximate straight line between the image captured by the first image capturing unit 101 and the image captured by the second image capturing unit 102 is compared. As a result of comparison, it is determined that an image having a larger inclination angle or bending angle is an image obtained by imaging the side surface of the living body 301 and an image having a smaller inclination angle or bending angle is determined by an image obtained by imaging the front surface of the living body 301. Subsequent steps 405 to 411 are the same as in the description of the first embodiment, and will be omitted.

As described above, the first imaging unit 101 and the second imaging unit 102 detect the state of the living body 301, and compare the state of the living body 301 (the inclination of the living body 301, the bending of the joint, etc.) The part of the living body 301 imaged by the imaging unit can be specified, and the subsequent biometric authentication process can proceed. In other words, the biometric authentication device 100 having the configuration of the third embodiment can perform biometric authentication processing regardless of the placement of the biometric 301, and thus is more convenient than the conventional biometric authentication device.
[Modification 1]
Hereinafter, Modification 1 of the first to third embodiments of the present invention will be described. FIG. 13 is a diagram illustrating a configuration of the biometric authentication device 100 including a third imaging unit 1301 in addition to the first imaging unit 101 and the second imaging unit 102.

By providing the third imaging unit, the authentication process can proceed even if the living body 301 rolls in any clockwise or counterclockwise direction with respect to an axis through which the living body 301 passes from the fingertip to the fingertip. In addition, since the number of imaging units for imaging the living body 301 is increased, information for calculating the tilt angle and the bending angle is increased, and the biological image can be corrected more accurately.
[Modification 2]
Next, modification 2 of the embodiment of the present invention will be described. FIG. 14 is a diagram illustrating an appearance of the biometric authentication apparatus 100 in which the position of the light source unit 103 is not the position where the living body 301 is irradiated from the side surface, but is changed to the position where the living body 301 is irradiated obliquely from above. . By disposing the light source on the oblique information of the living body 301, near-infrared light is evenly applied to the living body, and the tip of the living body 301 is not darkened. Therefore, it is possible to prevent a reduction in the resolution of the captured biological image.
[Modification 3]
Next, Modification 3 of the embodiment of the present invention will be described. In the third modification, the light source unit 103 includes two types. That is, the light source unit 103 may include an infrared LED that emits near-infrared light in order to acquire biological information, and a visible light LED that emits visible light in order to extract a contour line that determines inclination and bending. .
[Modification 4]
Next, Modification 3 of the embodiment of the present invention will be described. The modification 4 includes a movable mechanism (not shown), and the mechanism moves the first imaging unit 101 at the time of capturing a biological image, thereby capturing the first biological image and the second biological image with one imaging unit. It may be possible.

  In addition, this invention is not limited to an above-described Example or modification. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 100 ... Biometric authentication apparatus, 101 ... 1st imaging part, 102 ... 2nd imaging part, 103 ... Light source part, 104 ... Communication part, 105 ... Fingertip installation part, 106: finger placement unit, 110: control unit, 200 ... upper terminal, 301 ... biological body, 501 ... first biological image, 502 ... second biological image, 601 ... Scanning of image, 602 ... Contour position coordinates, 701 to 703 ... Approximate straight line, 704 ... Joint position, 801 ... Biological image after correction, 1101 ... Living body, 1301.・ Third imaging unit

Claims (9)

A living body installation unit where a user's living body is installed;
A light source unit that emits light to a living body installed in the living body installation unit;
An imaging unit that captures a first biometric image used for biometric authentication and a second biometric image used to calculate a correction coefficient for correcting the first biometric image;
A biometric authentication device comprising: control of each unit to be connected; and a control unit that calculates the correction coefficient and corrects the first biometric image using the correction coefficient. The biometric authentication device according to claim 1,
The control unit extracts an approximate straight line from the outline of the living body photographed in the second living body image,
An inclination angle of the approximate straight line is calculated with reference to an end of the second biological image, the correction coefficient is calculated using the inclination angle of the approximate straight line, and the first biological image is corrected. A biometric authentication device. The biometric authentication device according to claim 2,
When two first approximate lines and two approximate lines can be extracted, the control unit obtains a joint position where the first approximate curve and the second approximate line intersect from the second biological image. The correction coefficient is obtained based on the inclination angle of the first approximate line and the inclination angle of the second approximate line with the joint position of the corresponding first biological image as a boundary, and the first biological image is corrected. A biometric authentication device characterized by: The biometric authentication device according to claim 2 or 3,
The control unit calculates an inclination angle of the approximate line from an image captured by the imaging unit, and compares the inclination angle of the approximate line, whereby the image captured by the imaging unit is compared with the first biological image. A biometric authentication device that determines which one of the second biometric images. The biometric authentication device according to any one of claims 2 to 4,
The control unit performs extraction of an inclination angle of the approximate straight line and correction of the biometric authentication image for the biometric feature information image created from the first biometric image and the second biometric image. A biometric authentication device. The biometric authentication device according to any one of claims 1 to 5,
A communication unit that communicates with the host device
The biometric authentication device, wherein the control unit compares pre-registered authentication data transmitted from the host device via the communication unit with the corrected first biometric image. The biometric authentication device according to any one of claims 1 to 6,
The imaging unit further captures a third biological image used for calculation of a correction coefficient for correcting the first biological image,
The biometric authentication device, wherein the control unit corrects the first biometric image using the second biometric image and the third biometric image. A living body installation unit where a user's living body is installed;
A light source unit that is located on the side of the living body installation unit and that emits light;
An opening that is below the living body installation unit and that allows light from the light source to pass therethrough; a first imaging unit that is located below the opening and at a position parallel to the optical axis of light emitted by the light source unit When,
And a second imaging unit located in the vicinity of the first imaging unit. The biometric authentication device according to claim 8,
A control unit for controlling the device,
The first imaging unit captures a biological image on the front side of the living body,
The second imaging unit captures a biological image on the side surface of the biological body,
The control unit calculates the correction coefficient for correcting the front-side biometric image from the side-side biometric image, and corrects the front-side biometric image using the correction coefficient. .

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